Bidirectional stent and method of use thereof

Abstract

A bidirectional twistable stent is disclosed. The stent comprises a cylinder-shaped stent body having a plurality of axially arranged rows of struts encircling a central lumen and a plurality of flex connectors that connect at least two adjacent rows of struts in such a manner that allows the stent to be twisted clockwise or counter clockwise without causing deformation of any struts in the stent body. Also disclosed are the method of making the stent, method of using the stent, and a kit containing the stent.

1 - 40 . (canceled) 
     
     
         41 . A method of using a bidirectional stent, comprising the step of:
 placing the bidirectional stent in a treatment site in a compressed state; and   enlarging the bidirectional stent to an expanded state at the treatment site to immobilize the bidirectional stent,   wherein the bidirectional stent comprises:   a cylinder-shaped stent body comprising a plurality of axially arranged rows of struts encircling a central lumen and a plurality of axially arranged alternating rows of s-shaped connectors and rows of opposite s-shaped connectors encircling the central lumen,   wherein openings are between each of the s-shaped connectors arranged in alternating rows, and   wherein each row of s-shaped connectors is flanked on both sides by rows of opposite s-shaped connectors and each row of opposite s-shaped connectors is flanked on both sides by rows of s-shaped connectors,   wherein each of the rows of struts consists of struts inter-connected to form a wave-pattern with alternating peaks and troughs, wherein each peak has a tip and each trough has a bottom,   wherein each peak in a row of struts is connected at its tip to a peak at its tip in an adjacent row of struts by an s-shaped connector or opposite s-shaped connector,   wherein the s-shaped connectors in the same row of the s-shaped connectors have the same configuration, and   wherein when the bidirectional stent is in a resting state, each peak in each row of struts is attached to one end of an s-shaped connector or an opposite s-shaped connector that is attached at its other end to a facing peak of an adjacent row with the facing peak being at an angle to the each peak, and each of the s-shaped connectors or opposite s-shaped connectors has a body having a continuous curve with an inflexion point, and   wherein when the bidirectional stent is subject to twist, the rows of s-shaped connectors and opposite s-shaped connectors contract or expand in an alternating manner to form a peristaltic shape in the stent body, and the rows of s-shaped connectors or opposite s-shaped connectors that are contracting form a neck shape, and the rows of s-shaped connectors or opposite s-shaped connectors that are expanding form a peristaltic shape, and the neck shape has a lesser radius than the radius of the peristaltic shape at its greatest expanse, thus allowing the stent body to be reversibly twisted clockwise or counter-clockwise from one end of the stent body by a full turn without causing permanent deformation of the struts and the s-shaped connectors or opposite s-shaped connectors in the stent body.   
     
     
         42 . The method of  claim 41 , wherein each of the s-shaped connectors in the bidirectional stent has a length that is about 150% to 500% of the larger of the row width of the two rows of struts that are connected by the s-shaped connectors. 
     
     
         43 . The method of  claim 41 , wherein each of the s-shaped connectors in the bidirectional stent has a length that is about 300% of the larger of the row width of the two rows of struts that are connected by the s-shaped connectors. 
     
     
         44 . The method of  claim 41 , wherein the stent body of the bidirectional stent is covered with a biodegradable coating. 
     
     
         45 . The method of  claim 44 , wherein the biodegradable coating comprises chitosan. 
     
     
         46 . A method for making a bidirectional stent, comprising:
 slitting a cylinder-shaped tube with a laser to create a matrix of struts and connectors that form the bidirectional stent,   wherein the bidirectional stent comprises:   a cylinder-shaped stent body comprising a plurality of axially arranged rows of struts encircling a central lumen and a plurality of axially arranged alternating rows of s-shaped connectors and rows of opposite s-shaped connectors encircling the central lumen,   wherein openings are between each of the s-shaped connectors arranged in alternating rows, and   wherein each row of s-shaped connectors is flanked on both sides by rows of opposite s-shaped connectors and each row of opposite s-shaped connectors is flanked on both sides by rows of s-shaped connectors,   wherein each of the rows of struts consists of struts inter-connected to form a wave-pattern with alternating peaks and troughs, wherein each peak has a tip and each trough has a bottom,   wherein each peak in a row of struts is connected at its tip to a peak at its tip in an adjacent row of struts by an s-shaped connector or opposite s-shaped connector,   wherein the s-shaped connectors in the same row of the s-shaped connectors have the same configuration, and   wherein when the bidirectional stent is in a resting state, each peak in each row of struts is attached to one end of an s-shaped connector or an opposite s-shaped connector that is attached at its other end to a facing peak of an adjacent row with the facing peak being at an angle to the each peak, and each of the s-shaped connectors or opposite s-shaped connectors has a body having a continuous curve with an inflexion point, and   wherein when the bidirectional stent is subject to twist, the rows of s-shaped connectors and opposite s-shaped connectors contract or expand in an alternating manner to form a peristaltic shape in the stent body, and the rows of s-shaped connectors or opposite s-shaped connectors that are contracting form a neck shape, and the rows of s-shaped connectors or opposite s-shaped connectors that are expanding form a peristaltic shape, and the neck shape has a lesser radius than the radius of the peristaltic shape at its greatest expanse, thus allowing the stent body to be reversibly twisted clockwise or counter-clockwise from one end of the stent body by a full turn without causing permanent deformation of the struts and the s-shaped connectors or opposite s-shaped connectors in the stent body.   
     
     
         47 . The method of  claim 46 , wherein each of the s-shaped connectors in the bidirectional stent has a length that is about 150% to 500% of the larger of the row width of the two rows of struts that are connected by the s-shaped connectors. 
     
     
         48 . The method of  claim 47 , wherein each of the s-shaped connectors in the bidirectional stent has a length that is about 300% of the larger of the row width of the two rows of struts that are connected by the s-shaped connectors. 
     
     
         49 . The method of  claim 47 , wherein the cylinder-shaped tube is made from a metal or an alloy. 
     
     
         50 . The method of  claim 47 , wherein the cylinder-shaped tube is made from nitinol. 
     
     
         51 . The method of  claim 47 , further comprising the step of coating the matrix of struts and connectors with a biodegradable polymer coating. 
     
     
         52 . The method of  claim 51 , wherein the biodegradable polymer coating comprises chitosan. 
     
     
         53 . A stent kit, comprising:
 (1) a bidirectional stent that comprises:   a cylinder-shaped stent body comprising a plurality of axially arranged rows of struts encircling a central lumen and a plurality of axially arranged alternating rows of s-shaped connectors and rows of opposite s-shaped connectors encircling the central lumen,   wherein openings are between each of the s-shaped connectors arranged in alternating rows, and   wherein each row of s-shaped connectors is flanked on both sides by rows of opposite s-shaped connectors and each row of opposite s-shaped connectors is flanked on both sides by rows of s-shaped connectors,   wherein each of the rows of struts consists of struts inter-connected to form a wave-pattern with alternating peaks and troughs, wherein each peak has a tip and each trough has a bottom,   wherein each peak in a row of struts is connected at its tip to a peak at its tip in an adjacent row of struts by an s-shaped connector or opposite s-shaped connector,   wherein the s-shaped connectors in the same row of the s-shaped connectors have the same configuration, and   wherein when the bidirectional stent is in a resting state, each peak in each row of struts is attached to one end of an s-shaped connector or an opposite s-shaped connector that is attached at its other end to a facing peak of an adjacent row with the facing peak being at an angle to the each peak, and each of the s-shaped connectors or opposite s-shaped connectors has a body having a continuous curve with an inflexion point, and   wherein when the bidirectional stent is subject to twist, the rows of s-shaped connectors and opposite s-shaped connectors contract or expand in an alternating manner to form a peristaltic shape in the stent body, and the rows of s-shaped connectors or opposite s-shaped connectors that are contracting form a neck shape, and the rows of s-shaped connectors or opposite s-shaped connectors that are expanding form a peristaltic shape, and the neck shape has a lesser radius than the radius of the peristaltic shape at its greatest expanse, thus allowing the stent body to be reversibly twisted clockwise or counter-clockwise from one end of the stent body by a full turn without causing permanent deformation of the struts and the s-shaped connectors or opposite s-shaped connectors in the stent body; and   (2) instructions for using the bidirectional stent.   
     
     
         54 . The kit of  claim 53 , further comprising a guidewire.